It is well known that film dailies or rushes are conventionally produced as a motion picture is shot. These dailies or rushes are processed and then viewed by the director, the producer, the film editor, etc. working on the production to determine whether the scenes shot are acceptable. Each person on the production team assesses the dailies for different elements relevant to their respective roles in the team.
"Printer Light" information is also provided which assists the cinematographer/director of photography to determine whether the scenes were shot with a satisfactory exposure. This Printer Light information is determined from the settings of a conventional motion picture film printer required to produce a print with laboratory aim densities. This information is obtained by passing white light from a scene through dichroic filters to split the light into its three components, red, green and blue. The three light components are then used to expose a test film strip from which the densities corresponding to the intensities of the red, green and blue components of the light can be measured and compared with standard densities which correspond to an "ideal" exposure. The densities produced by the red, green and blue light components on the test film strip give an indication of the exposure given to the original film as the scene was recorded. Printer Light information provides values between 0 and 50, the neutral values being 25, 25, 25 and correspond to the ideal exposure. Printer Light values greater than or less than the neutral values correspond to over- or under-exposed scenes respectively, with each Printer Light unit corresponding to 0.025 units in Log Exposure.
However, there is an increasing demand for motion picture negative film to be transferred to video, and the film is never printed as such, as most film programs made specifically for television, for example, episodic shows, movies of the week and commercials, are transferred to video tape prior to showing. Telecine machines enable this transfer to be achieved. Furthermore, in feature film production, video dailies are replacing the film dailies or rushes and non-linear editing techniques are replacing conventional film editing.
When transferring negative film to video tape, the colorist, operator of a telecine, needs to adjust the settings of the telecine, in particular, gamma (or contrast), lift (or detail in the black areas of the scene) and gain (or brightness), so that the transfer of the film is optimized. This may be time-consuming if the film has not been correctly exposed, the color balance is incorrect etc., and adjustments have to be made. Several film test targets have been developed which are designed to assist the set up and maintenance of telecine equipment, and thereby offer operators nominal starting points for a film to video transfer session. Such targets, such as Eastman Kodak Company's Telecine Analysis Film (TAF), typically include a color bar test pattern and a neutral gray scale.